Radiotelegraph transmitting system.



0, c. R008. RADIOTELEGRAPH TRANSMITTING SYSTEM.

APPLICATTDN FILED JULY T4. 19H.

1;?375L5Q? Patented Sept". 10, 1918.

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RADIOTELEGRAPH TRANSMITTING SYSTEM.

Application filed July 1 2, 1917.

To all whom it may concern.

Be it known that I, OSCAR C. R005, a citizen of the United States, and aresident of Allston, in the county of Suffolk and State ofMassachusetts, have invented a new and useful Improvement inRadiotelegraph Transmitting Systems, of which the following is aspecification.

My invention relates to radio-telegraph transmitting systems, and itsobjects are to provide a system in which the discharge of theoscillating circuit condenser may be readily controlled over a widetonerange and otherwise to improve such systems and increase theeflieiency thereof.

Three illustrative embodiments of my invention are shown conventionallyin the accompanying drawings; but it will be understood that variousmodifications may be made both in the apparatus and the system ofcircuits without departing from the principle of my invention.

In the drawingsv Figure 1 is a diagram of a radio-telegraph transmittingsystem involving my invention; and Figs. 2 and 3 are diagrams ofmodifications.

A transmitting antenna T is associated in any suitable way with anoscillation-producing circuit and is grounded at E.

In Fig. 1 a condenser C" is connected in series with an inductance L" aradiofrequency generator A", which may be either a high-frequencyalternator or an arc, a spark gap S, which as shown may be placed in thefield of the magnet M or else in a vessel containing a compressed gas,and two trigger valves or arresters V, V, one on either side of saidspark gap.

I may employ as an arrester a spark gap or a quenched spark gap, ortwo'oppositely arranged rectifiers such. as a point and plate rectifier,a .hot and cold electrode rectifier, a mercury vapor rectifier, or analuminum or other film arrester, etc. For illustrative purposes only Ihave shown in Figs. 1 and 3 two opposed point and plate rectifiers V, Vand in Fig. 2 two quenched spark gaps S, S". I do not limit myself as tothe kind, number orarrangement of the arresters employed, for my objectmay be accom--'-- plished by a variety of devices which will servenormally to prevent the condenser from discharging across the spark gap,which are capable of being rendered ineffective by being broken down bya momenvention shown in Figs. 2, and 3 it Specification of LettersPatent. Pgat@nte fi $313 5. 1 39, fifilg.

Serial Ho. 180,523.

tary impulse from an auxiliary source, and which regain theireffectiveness immediately upon the cessation of such impulse.

The auxiliary source which I prefer consists as shown of two'low-voltagealternating-current generators A, A, of di ferent frequencies connected,respectively, in series with the adjustable condenser C and adjustablecoil L, and the adjustable condenser C and the adjustable coil L, thecircuit of each generator being attuned approximately to the frequencyof current developed therein. By means of the coil L in inductiverelation to the coils L, L, the latter not being in inductive relationwith each other, said circuits may be thrown into resonance with thecurrents developed by their respective generators when the key K isclosed.

The circuits of the generators are connected with the arresters,respectively, so that the potential resulting from resonance will actupon them or break them down, and thereby render them ineffective. Inthe present instance the condensers C, C are connected, respectively,with the arrests-rs V, V, or S, S, by leads which'include the chokecoils l, I, or I, 1, respectively.

in Figs. 2 and 3 the condenser is charged by a direct current generatorG, which is protected by the choke coils l, I, and is connected inseries with the quenched spark gap S.

The operation is follows: Neither the high-frequency generator A nor thedynamo G can breakdown a larger gap than S or S and the arresters,therefore, prevent the discharge of the condenser C across the gapunless they are simultaneously broken down. They will be simultaneouslybroken down 2 (n m) times a second where a and m represent thefrequencies of the generators A, A respectively, so that the toneproduced in the receiving system will be the beat frequency of saidgenerators, and this tone, as will be obvious, may be widely varied byslightly altering the speed of one or both generators. My invention willthus be-seen to afford a very simple and flexible electrical substitutefor various mechanical devices such as the transmitting tone wheel, theZOtfllllllgfil'lfilk 'gap, etc, for securing different tone effects.

In the case of the embodiments of my ingenerally desirable to use agenerator G which has a falling voltage characteristic in order Tilt! toavoid the possibility of arcing in the gap Hav'rn described illustrativeembodlments 0 my invention Without however source of electrical energyarranged to charge said condenser, two arresters in said circuit one oneither side of said spark gap, for preventing the discharge of saidcondenser'across said gap, a transmitting key, and means controlled bysaid key for simultaneously breaking down both arresters.

2. A radio-telegraph transmitting system, comprising in combination acircuit provided with a condenser and a spark gap, a source ofelectrical energy arranged to charge said condenser, two electric valvesin said circuit, one on either side of said spark gap, for preventingthe discharge of said condenser across said gap, a transmitting key, andmeans controlled by said key for simultaneously breaking down both ofsaid valves. g

3. A radio-telegraph transmitting system,

comprising in combination a circuit pro-- vided with a condenser and aspark gap, a

source. of electrical energy arranged to charge said condenser,'twoarresters in said circuit, one on either side of said spark gap,-

-a source of electrical energy arranged to charge said condenser, twoarresters in said circuit, one on either slde of said spark gap, forpreventing the dischargeof said condenser across said gap, alternatingcurrent generators of different frequencies, circuits attunedapproximately to the frequencies of said generators, respectively,connections from said circuits. to said arresters, respectively, and keycontrolled means for throwing the last named circuits into resonancewith the currents developed by their respective generators.

- In testimony whereof I have hereunto subscribed my name this 2nd dayofuly, 1917.

OSCAR 0. Boos.

